Potentiometers of the kind described are known from the following publications: DE-OS 34 44 229, DE-OS 35 24 308, EP 0 124 346 A2, GB 21 22 033, and the earlier patent application P 36 24 364.9 which is not a prior publication.
A possibility of adjusting the potentiometer is described in DE-OS 34 44 229 and, for this purpose, an intermediate carrier is provided which is rotatable with respect to the spring carrier and to which the slider spring is riveted. All this permits is adjustment of the "zero position" of the potentiometer, while its resistance value cannot be trimmed.
In the case of GB 21 22 033 it is known to trim the resistor path by a fine cut which extends radially with respect to the curved resistance path and is located outside of the area swept over by the sliding contact of the slider spring.
That has the disadvantage that the electrical resistance value of the resistor path must be fixed prior to installing the resistor core in the potentiometer so that further factors of influence, like the contact pressure between the slider spring and the resistor path cannot be allowed for. In spite of possible adjustment, therefore, the tolerances of the electrical values of the potentiometer still are considerable.